Simple Algorithm Flow for OCR ID Card Recognition

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Conducting research on OCR ID card recognition, I will organize the algorithm flow from the perspective of basic image processing.

Introduction to OCR

• Optical Character Recognition (OCR)

• The goal is to analyze and recognize characters in images, converting them into a sequence of text characters.

• Utilizes pattern recognition and digital image processing techniques to solve text input problems.

Classification by Input Method

• Printed Text

• Handwritten Text (input via scanner/input via graphics tablet)

Classification by Recognizable Character Set

• English, Chinese, Japanese, Korean, etc.

• Chinese, commonly used 4000 characters, various fonts, similar characters are difficult to distinguish

Application-Oriented OCR

• Licenses, receipts, documents, business cards, ID cards, driver’s licenses, automotive manufacturing.

ID Card Recognition

A typical algorithm flowchart for ID card recognition is as follows:

Image Preprocessing

• Denoising filtering, illumination processing

• Enhancement (optional) gray stretching

• Binarization converting grayscale images to binary images

• Skew correction Hough transform, projection method

Image Segmentation

• Line segmentation

  The character information distribution rules in ID card images, with a certain gap between each line; using horizontal projection method for image segmentation

• Character segmentation

  Vertical projection

Character Recognition

• Template matching method

  Establish a standard template for each character, performing graphic matching, stroke matching, and geometric feature matching. Characteristics: simple implementation, high image quality requirements, slow computation speed, low recognition rate for similar characters

• Artificial Neural Network Character Recognition Algorithm

  Artificial neural network, referred to as neural network, is a mathematical model or computational model that mimics the structure and function of biological neural networks.

Recognition Result Processing

– ID card number verification

– Validity verification

ID Card Recognition Software

• Yunmai

• WenTong

• Abbyy

• ……

The recognition effect is significantly correlated with photo clarity, tilt, background, lighting, contrast, etc.

The author is CSDN blogger maowenbei

Link: https://blog.csdn.net/maowenbei/article/details/72765647

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